Unix Timestamp Converter
Convert between Unix timestamps (epoch seconds/milliseconds) and human-readable dates. Your browser's timezone is shown explicitly.
Notable timestamps:
Seconds and milliseconds are detected automatically.
What is a Unix timestamp?
A Unix timestamp (also called epoch time) is the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC — a point in time called the Unix epoch. It provides a timezone-independent, unambiguous way to represent a moment in time.
Seconds vs. milliseconds
Most Unix APIs use seconds (e.g. 1700000000). JavaScript's Date.now() and many frontend APIs use milliseconds (e.g. 1700000000000). This tool detects which unit you're using based on the magnitude of the number.
Timezone handling
Unix timestamps are always UTC. When converting to a local datetime, the result depends on your browser's configured timezone, which is displayed alongside the converted value. No timezone data is sent to a server.
Common use cases
- Reading
iat(issued at) andexp(expires) fields in JWTs - Interpreting API response timestamps
- Debugging scheduled jobs and cron expressions
- Comparing log timestamps across services
Frequently Asked Questions
What is a Unix epoch timestamp?
A Unix timestamp is the number of seconds that have elapsed since January 1, 1970 00:00:00 UTC (excluding leap seconds). It is the universal standard for system clocks, databases, and network protocol timestamps.
How can I tell seconds from milliseconds in a timestamp?
A 10-digit integer (around 1.7×10^9) indicates seconds (standard in Unix, Python, Go, and PHP). A 13-digit integer indicates milliseconds (standard in JavaScript Date.now() and Java). This tool automatically detects both formats.
What is the Year 2038 problem (Y2038)?
On January 19, 2038 at 03:14:07 UTC, legacy 32-bit signed integers will overflow into negative values. Modern 64-bit operating systems and JavaScript Numbers (64-bit float) avoid this overflow completely.
How are timezones handled?
Epoch timestamps are UTC-absolute. When translating to human-readable text, the tool presents both UTC and your device's local timezone using the browser's native Intl API.